Mathematica permits divider lines between rows and columns in a table
(grid) such
as this example from the documentation:
Grid[Table[x, {4}, {11}], Dividers -> {{{{True, False}}, -1 -> True},
False}]
But, the dividers are single lines only.
Sometimes double line dividers are desired
as shown in this table on the Web:
http://www.assetcorrelation.com/user/correlations/90
Notice that the background color for an item is only within
the inside line of a double line divider.
Is there any way to produce (a) this kind of divider (double line)
and (b) with background colors for specific items that don't cross
the inside line of the double line divider?
Thank you in advance.
Don